Device, system and method for calibrating a non-invasive health monitoring device

ABSTRACT

A system for calibrating a device for measuring materials concentration in the blood is disclosed. The system may include at least two sets of calibrating elements, each set may include a plurality of calibrating elements. Each of the calibrating elements in the sets may include, a first layer simulating a specific human skin characteristics; and a second layer consisting a specific concentration of one or more materials in the blood. For all calibrating elements in a set the first layer may be the same first layer simulating the same human skin characteristics such that each set of calibrating elements simulate different skin characteristics. Each calibrating element in a set of calibrating elements may include a different second layer consisting a different concentration of the one or more materials. The system may further include a controller.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Phase Application of PCT InternationalApplication No. PCT/IL2017/051115, International Filing Date Oct. 2,2017, claiming the benefit of U.S. Patent Application No. 62/404,813,filed Oct. 6, 2016, which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

Noninvasive blood test measurements are the future of bloodmeasurements. They are simple, harmless, unpainful and do not involvelaboratory time. Several commercial products for noninvasivemeasurements are available today. However, for these devices to workproperly they must be accurately calibrated to suit specific patients.

Noninvasive blood test measurements are performed by attaching ameasurement device to the patient's skin. These devices are usuallyoperated by sending electromagnetic signals (e.g., visual light, IRradiation, RF radiation, etc.) via the patient skin targeting a bloodvessel and reading reflection received from the blood vessel. Differenthumans' skin has different characteristics, such as, differentthicknesses of different skin layers, different amount of hair,different amount of pigment etc., and therefore may absorb differentlythe electromagnetic signals sent from the noninvasive measurementsdevice. Accordingly, there is a need for a noninvasive blood measurementdeceive that may be calibrated specifically to each user so to measureaccurately, concentrations of various materials in the blood forpatients with different skin characteristics and different anatomy.

SUMMARY

Some aspects of the invention are directed to a system for calibrating adevice for measuring materials concentration in the blood. The systemmay include at least two sets of calibrating elements, each setcomprising a plurality of calibrating elements. In some embodiments,each of the calibrating elements may include, a first layer simulating aspecific human skin characteristics; and a second layer consisting aspecific concentration of one or more materials in the blood. In someembodiments, all calibrating elements in a set the first layer may bethe same first layer simulating the same human skin characteristics suchthat each set of calibrating elements simulate different skincharacteristics. In some embodiments, each calibrating element in a setof calibrating elements may include a different second layer consistinga different concentration of the one or more material. In someembodiments, the system may further include a controller that may beconfigured to: receive illumination intensities from the device formeasuring materials concentration when the device is attached to eachcalibrating element of the system; associate the received illuminationintensities with the specific skin characteristics and the specificconcentration of the calibrating element to which the device isattached; and save the illumination intensities associated with thespecific skin characteristics and the specific concentration in lookuptables in a memory of the device for measuring materials concentration.

In some embodiments, the skin characteristic may be at least one of:skin thickness, skin color, skin hair density, skin tone, skintemperature, skin optical properties and skin hair color. In someembodiments, the received illumination intensities may includeillumination intensities at various wavelengths and the saved lookuptables include lookup tables for illumination intensities of a specificwavelength associated with the specific skin characteristics, the one ormore materials and the specific concentration. In some embodiments, thesystem may further include a third layer for simulating illuminationreflection from a blood vessel in a skin tissue.

Some other aspects of the invention may be related to a system forcalibrating a device for measuring materials concentration in the blood.The system may include a first sets of calibrating elements and a secondset of calibrating elements. In some embodiments, each of thecalibrating elements in the first and second sets may include a firstlayer simulating a specific human skin characteristic; and a secondlayer consisting a specific concentration of one or more materials inthe blood, such that in the first set of calibrating elements the firstlayer simulates a first human skin characteristic and in the second setof calibrating elements the first layer simulates a second human skincharacteristic, different from the first human skin characteristic. Insome embodiments, wherein each calibrating element in the first set mayinclude a different second layer consisting a different concentration ofthe one or more materials, and each calibrating element in the secondset may include a different second layer consisting a differentconcentration of the one or more materials. In some embodiments, thesystem may further include a controller that may be configured to:receive illumination intensities from the device for measuring materialsconcentration when the device is attached to each calibrating element ofthe system; associate the received illumination intensities with thespecific skin characteristic and the specific concentration of themeasured one or more materials in the second layer of the calibratingelement to which the device is attached; and save the illuminationintensities associated with the specific skin thicknesses and thespecific concentrations in a memory of the device for measuringmaterials concentration.

In some embodiments, the skin characteristic is at least one of: skinthickness, skin color, skin hair density, skin optical properties, andskin hair color.

Some additional aspects of the present invention may be related to amethod of calibrating a device for measuring materials concentration inthe blood. The method may include: attaching the device for measuringmaterials concentration to each calibrating element included in one oftwo or more sets of calibrating elements. In some embodiments, each ofthe calibrating elements may include: a first layer simulating aspecific human skin characteristic; and a second layer consisting aspecific concentration of one or more materials. In some embodiments, inall calibrating elements in a set the first layer may be the same firstlayer simulating the same human skin characteristic and each set ofcalibrating elements simulate different skin characteristic, and eachcalibrating element in a set of calibrating elements may include adifferent second layer consisting a different concentration of the oneor more materials. In some embodiments, the method may further include:receiving, by a controller of a calibrating system, illuminationintensities from the device for measuring materials concentration whenthe device is attached to each calibrating element; associating, by thecontroller, the received illumination intensities with the specific skincharacteristic and the specific concentration of the one or morematerials in the second layer of the calibrating element to which thedevice is attached; and recording, by the controller, the illuminationintensities associated with the specific skin characteristic and thespecific concentrations in a memory of the device for measuringmaterials concentration.

In some embodiments, receiving illumination intensities may includereceiving illumination intensities at various wavelengths and recordingthe illumination intensities may include creating lookup tables forillumination intensities of a specific wavelength associated with thespecific skin characteristic and the specific concentration.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter regarded as the invention is particularly pointed outand distinctly claimed in the concluding portion of the specification.The invention, however, both as to organization and method of operation,together with objects, features, and advantages thereof, may best beunderstood by reference to the following detailed description when readwith the accompanying drawings in which:

FIG. 1 is diagrammatic representation of a system for calibrating adevice for measuring materials concentration in the blood according tosome embodiments of the invention;

FIG. 2 is an illustration of a measurement device according to someembodiments of the invention;

FIG. 3 is an illustration of a calibrating element according to someembodiments of the invention; and

FIG. 4 is a flowchart of a method of calibrating a device for measuringmaterials concentration in the blood according to some embodiments ofthe invention.

It will be appreciated that for simplicity and clarity of illustration,elements shown in the figures have not necessarily been drawn to scale.For example, the dimensions of some of the elements may be exaggeratedrelative to other elements for clarity. Further, where consideredappropriate, reference numerals may be repeated among the figures toindicate corresponding or analogous elements.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the invention.However, it will be understood by those skilled in the art that theinvention may be practiced without these specific details. In otherinstances, well-known methods, procedures, and components modules, unitsand/or circuits have not been described in detail so as not to obscurethe invention. Some features or elements described with respect to oneembodiment may be combined with features or elements described withrespect to other embodiments. For the sake of clarity, discussion ofsame or similar features or elements may not be repeated.

Although embodiments of the invention are not limited in this regard,discussions utilizing terms such as, for example, “processing,”“computing,” “calculating,” “determining,” “establishing”, “analyzing”,“checking”, or the like, may refer to operation(s) and/or process(es) ofa computer, a computing platform, a computing system, or otherelectronic computing device, that manipulates and/or transforms datarepresented as physical (e.g., electronic) quantities within thecomputer's registers and/or memories into other data similarlyrepresented as physical quantities within the computer's registersand/or memories or other information non-transitory storage medium thatmay store instructions to perform operations and/or processes. Althoughembodiments of the invention are not limited in this regard, the terms“plurality” and “a plurality” as used herein may include, for example,“multiple” or “two or more”. The terms “plurality” or “a plurality” maybe used throughout the specification to describe two or more components,devices, elements, units, parameters, or the like. The term set whenused herein may include one or more items. Unless explicitly stated, themethod embodiments described herein are not constrained to a particularorder or sequence. Additionally, some of the described methodembodiments or elements thereof can occur or be performedsimultaneously, at the same point in time, or concurrently.

Reference is now made to FIG. 1 which is a diagrammatic representationof a system for calibrating a device for measuring materialsconcentration in the blood according to some embodiments of theinvention. System 100 may include at least two sets 105 and 106 ofcalibrating elements 105 a-105 d and 106 a-106 d. In some embodiments,system 100 may include additional sets, for example, set 107, ofcalibrating elements 107 a-107 d. A detailed description of acalibrating element is given with respect to FIG. 3 . System 100 mayfurther include a controller 110, a storage unit 120 a user interface130 and a communication unit 140. Communication unit 140 may beconfigured to send and receive information from a device 10 formeasuring materials concentration in the blood.

In some embodiments, controller 110 may include a processor 112 that maybe, for example, a central processing unit (CPU), a chip or any suitablecomputing or computational device, an operating system 114 and a memory116. System 100 may include a desktop computer, laptop commuter, atablet, a mainframe computer or the like. Processor 112 may beconfigured to carry out methods according to embodiments of the presentinvention by for example executing instructions stored in a memory suchas memory 116.

Operating system 114 may be or may include any code segment designedand/or configured to perform tasks involving coordination, scheduling,arbitration, supervising, controlling or otherwise managing operation ofcontroller 110, for example, scheduling execution of programs. Operatingsystem 114 may be a commercial operating system. Memory 116 may be ormay include, for example, a Random Access Memory (RAM), a read onlymemory (ROM), a Dynamic RAM (DRAM), a Synchronous DRAM (SD-RAM), adouble data rate (DDR) memory chip, a Flash memory, a volatile memory, anon-volatile memory, a cache memory, a buffer, a short term memory unit,a long term memory unit, or other suitable memory units or storageunits. Memory 116 may be or may include a plurality of, possiblydifferent memory units.

Memory 116 may store any executable code, e.g., an application, aprogram, a process, task or script. The executable code may includecodes for calibrating a device for measuring materials concentration inthe blood or any other codes or instruction for executing methodsaccording to embodiments of the present invention. The executable codemay be executed by processor 112 possibly under control of operatingsystem 114.

Storage 120 may be or may include, for example, a hard disk drive, afloppy disk drive, a Compact Disk (CD) drive, a CD-Recordable (CD-R)drive, a universal serial bus (USB) device or other suitable removableand/or fixed storage unit. Content may be stored in storage 120 and maybe loaded from storage 120 into memory 116 where it may be processed byprocessor 112. For example, storage 120 may include reference datarelated to measuring materials concentration in the blood, such asamplitude of reflected IR light in different wave lengths, representing:glucose blood levels, LDL (low density lipoproteins) levels in theblood, HDL (high density lipoprotein) levels in the blood, cholesterollevels in the blood, TG (Tri Glycerides) levels in the blood, Albuminlevels in the blood, Hemoglobin levels in the blood, cardiac pulsefrequency, cardiac pulse signal intensity, skin temp rate, body movementor lack of movement, body acceleration in different directions,horizontal positioning, skin thickness, skin pigmentation,

User interface 130 may be or may include a screen, a pointing device andan audio device or any other device that may allow a user to sendinstructions and/or information to controller 110 and receiveinformation from controller 110. For example, user interface 130 mayinclude, a mouse, a touch screen or a pad, a keyboard, a microphone,speakers and the like.

In some embodiments, system 100 may further include a communication unit140 for communication with at least one device 10 for measuringmaterials concentration in the blood. Communication unit 140 may includeany applicable input/output (I/O) devices to connected controller 110and device 10, for example, a wired or wireless network interface card(NIC), a modem, a universal serial bus (USB) device or external harddrive and the like.

Embodiments of the invention may include an article such as a computeror processor non-transitory readable medium, or a computer or processornon-transitory storage medium, such as for example a memory, a diskdrive, or a USB flash memory, encoding, including or storinginstructions, e.g., computer-executable instructions, which, whenexecuted by a processor or controller, carry out methods disclosedherein.

The storage medium may include, but is not limited to, any type of diskincluding floppy disks, optical disks, compact disk read-only memories(CD-ROMs), rewritable compact disk (CD-RWs), and magneto-optical disks,semiconductor devices such as read-only memories (ROMs), random accessmemories (RAMs), such as a dynamic RAM (DRAM), erasable programmableread-only memories (EPROMs), flash memories, electrically erasableprogrammable read-only memories (EEPROMs), magnetic or optical cards, orany type of media suitable for storing electronic instructions,including programmable storage unit.

A system according to embodiments of the invention may includecomponents such as, but not limited to, a plurality of centralprocessing units (CPU) or any other suitable multi-purpose or specificprocessors or controllers, a plurality of input units, a plurality ofoutput units, a plurality of memory units, and a plurality of storageunits. A system may additionally include other suitable hardwarecomponents and/or software components. In some embodiments, a system mayinclude or may be, for example, a personal computer, a desktop computer,a mobile computer, a laptop computer, a notebook computer, a terminal, aworkstation, a server computer, a tablet computer, a network device, orany other suitable computing device. Unless explicitly stated, themethod embodiments described herein are not constrained to a particularorder or sequence. Additionally, some of the described methodembodiments or elements thereof can occur or be performed at the samepoint in time.

Reference is now made to FIG. 2 which is an illustration of a device formeasuring materials concentration in the blood according to someembodiments of the invention. Device 10 may be a wearable monitoringdevice configured to measure concentration of materials such as,glucose, albumin, insulin and the like, in a user's blood. Device 10 mayinclude a measuring unit 200, a processor 230, a communication unit 240and a memory 250. Measuring unit 200 may include at least one sensor 210and at least one light emitting source 220. In some embodiments,measuring unit 200 may be adjacent to and in contact with the skin of asubject so as to reduce noise from the environment. It should be notedthat with light emitted from the at least one light emitting source 220,device 10 may perform optical measurements that are noninvasive incontrast to commercially available invasive and minimal invasivesolutions.

According to some embodiments, the EM radiation emitted from the atleast one light emitting source 220, may be reflected from asubcutaneous tissue of the subject, and then detected by the at leastone sensor 210 that may be, according to some embodiments, in theInfra-Red or near Infra-Red (IR) spectrum. For example, Short Wave IR(SWIR) imaging is utilized for measuring physiological signals from theblood of a subject. The SWIR waveband runs from the lower edge of thenear IR region at 900 nm up to 2500 nm, and may be utilized forinspection of blood vessels in the body of the subject. It should benoted that if required, the range of the SWIR waveband may be increased.

It should be noted that device 10 may include measuring unit 200 invarious configurations, and in some embodiments a single sensor 210 issurrounded by a plurality of light emitting sources 220 (as for exampleillustrated in FIG. 2 ). Other configuration may also employ a pluralityof sensors 210 and light emitting sources.

In some embodiment, each light emitting source 220, or sub-sets (e.g.pairs, triplets etc.) of light emitting sources 220 may emit light in adifferent predetermined wavelength.

In some embodiment, each light emitting source 220, or sub-set of lightemitting sources 220, may emit light in a different time and/or in adifferent frequency, such that not all light emitting sources 220 emitlight simultaneously. This may provide additional information on thereflected tissue when the time intervals between the emissions of lightbeams are known.

According to some embodiments, the frequency of sampling by each lightemitting source 220, or by each sub-set of light emitting sources 220,may be equal to or higher than Nyquist rate of the measuredphysiological signal.

In some non-limiting embodiments, polarized optical means may beutilized in order to increase the accuracy in the optical measurements.Specifically, emitting light beams with a predetermined polarization andreceiving these beams with a substantially different polarization, forinstance with dedicated filters, may improve the signal to noise ratioin the measurements. Furthermore, such polarizing may also provideimproved indication on the penetration of the light beam into the tissueas noises from the external skin layer may be reduced while only signalsfrom the beam reflected of the blood vessels is measured.

In some non-limiting embodiments, other sensors may also be utilized.For example acoustic ultrasound sensors, as well as terahertz sensors,RF sensors, microwave sensors and corresponding energy sources.

Reference is now made to FIG. 3 which is an illustration of acalibrating element according to some embodiments of the invention. Acalibrating element 300 may include a first layer 310 simulating aspecific human skin characteristics and a second layer 320 consisting aspecific concentration of one or more materials in the blood, forexample, glucose, albumin and insulin or a combination thereof. In someembodiments, the specific concentration may include specificconcentrations of more than one material, for example, albumin andinsulin. Skin characteristic according to embodiments of the inventionmay include at least one of: skin thickness, skin temperature skincolor, skin hair density, skin optical properties, and skin hair color.In some embodiments, the skin optical properties may include the abilityof the skin to absorb, reflect and/or scattered EM radiation, forexample, short wave infrared. The skin optical properties may includethe scattering parameter (S-parameters) matrix.

In some embodiments, calibrating element 300 may further include a thirdlayer 330 for simulating illumination reflection from a blood vessel ina skin tissue and for isolating the element from noise and reflectionsnot related to the measured one or more materials in the second layer.Calibrating element 300 may include substantially the same types oflayers as calibrating elements 105 a-105 d, 106 a-106 d and 107 a-107 billustrated in FIG. 1 . In some embodiments, calibrating element 300,105 a-105 d, 106 a-106 d and 107 a-107 b may be configured to allowdevice 10 to be attached to the calibrating element in such a way thatexternal light radiation does not interfere with the sent EM radiationand read EM reflections from the calibrating element. For example,calibrating element 300, 105 a-105 d, 106 a-106 d and 107 a-107 b mayhave a cylindrical shape to emulate the form of a human wrist or arm.Other shapes may be used.

First layer 310 may include any material that may simulate the EMabsorption properties of the human skin. For example, first layer 310may include materials that simulate melanin chromophores, skin proteins(collagen, elastin), water, blood lipids, hemoglobin or other bloodcomponents, that may simulate the reaction of a human skin to EMradiation emitted from one or more emitting sources 220. Some ofcalibration elements 300 may have different first layers simulatingdifferent skin characteristics. In some embodiments, sets 105, 106 and107 may vary in the simulated thickness for example, elements 105 a-105d may all have the same first layer simulating a skin thickness of 2 mm;elements 106 a-106 d may all have the same first layer simulating a skinthickness of 3 mm and elements 107 a-107 d may all have the same firstlayer simulated a skin thickness of 5 mm In some embodiments, system 100of FIG. 1 may include sets having skin thicknesses of 2, 2.25, 2.5,2.75, 3, 3.25 . . . 4.75 and 5 mm.

In some embodiments, at least some of the sets of calibrating elementsmay simulate different skin color & tone in addition to different skinthickness. For example, set 106 and set 107 may both simulate a skinthickness of 2.5 mm but with different amount of color pigment such asmelanin chromophores, hemoglobin, other blood components, skin proteins(Elastin, collagen) etc.

Second layer 320 may include a liquid or solid solution comprising aspecific concentration of one or more materials to be measured in theblood. For example, second layer 320 may include a specificconcentration of albumin and/or glucose. In some embodiments, eachcalibrating element in a set of calibrating elements may include adifferent second layer having a different concentration of the one ormore materials. For example, calibrating element 105 a may include 3.5g/dL of albumin, element 105 b may include 3.6 g/dL of albumin, element105 c may include 3.7 g/dL of albumin and element 105 d may include 3.8g/dL of albumin. Similar or different albumin concentrations may beincluded in elements 106 a-106 d and 107 a-107 d. In yet anotherexample, elements 106 a-106 d and 107 a-107 d may include differentconcentrations of albumin and glucose. It should be appreciated thatwhile the example illustrated in FIG. 1 each set of elements 105, 106,107 includes 4 calibration elements, any number of calibrating elementsmay be used in each set. Furthermore, it should be appreciated thataccording to some embodiments, different sets may have different numberof calibrating elements.

Third layer 330 may include any material that will isolate and absorbthe electromagnetic radiation emitted from one or more emitting source220 the way a human organ/skin will do. For example, third layer 330 mayinclude wood aluminum, metal, SWIR (short-wavelength infrared) opaquepolymers and water.

Reference is now made to FIG. 4 which is a flowchart of a method ofcalibrating a device for measuring materials concentration in the bloodaccording to some embodiments of the invention. The method of FIG. 4 maybe performed using a system such as system 100. In operation 410,embodiments may include attaching the device for measuring materialsconcentration to each calibrating element included in two or more setsof calibrating elements. Device 10 may be attached, manually orautomatically (e.g., by a robotic system) to at least some of thecalibrating elements of system 100. For example, device 10 may beattached first to each of calibrating elements 105 a-105 d of set 105and then be attached to each of calibrating elements 106 a-106 d of set106, and so on.

In some embodiments, each time device 10 is being attached to acalibrating element, one or more light emitting sources 220 may emit EMradiation (e.g., light) into the calibrating element and one or moresensors 210 may read EM radiation reflected back from the calibratingelement. Processor 230 may record in memory 250 the intensity (e.g., anoptical value) at which the reflected EM radiation was sensed by one ormore sensors 210. In some embodiments, one or more light emittingsources 220 may emit light at several wavelengths, for example, at 1100nm and 1290 nm and sensor 210 may sense two different intensities (e.g.,different optical values) for each wavelength. In some embodiments,processor 230 may be configured to send via communication unit 240 therecorded intensities to controller 110.

In operation 420, embodiments may include receiving illuminationintensities from the device for measuring materials concentration whenthe device is attached to each calibrating element. In some embodiments,the illumination intensities may be affected by the opticalcharacteristics of at least first layer 310 and second layer 320. The EMradiation reflected from second layer 320 may be affected by the abilityof the material or materials in layer 320 (e.g., albumin and/or glucose)to absorb the EM radiation and the scattering, absorbing and reflectingproperties of first layer 310. Processor 110 may receive from device 10,via communication unit 140 the sensed illumination intensities, sensedby sensor 210 for each calibrating element separately. Processor 110 mayfurther receive information regarding form which calibrating element theillumination intensities was received and at which wavelength. In someembodiments, each calibrating element may be marked with a machinereadable tag such as an RFID tag, a barcode or the like. In someembodiments, system 100 may further include a tag reader incommunication with controller 110 that are configured to read anidentification code included in the machine readable tag.

Accordingly, processor 110 may associate the received illuminationintensities with the specific skin characteristics and the specificconcentration of the calibrating element to which the device isattached, in operation 430.

An example for intensities (optical values) recorded for variouscalibrating elements at two wavelengths is given in table 1. Thecalibrating elements of table 1 includes at least two layers, a firstlayer simulating the skin thickness (2 mm for set 105 and 2.25 mm forset 106) and a second layer comprising albumin at concentrations of3.5-3.7 g/dL.

TABLE 1 Wavelength of 1100 nm Wavelength of 1290 nm Albumin OpticalAlbumin Optical concentration value concentration value element [g/dL][mW] element [g/dL] [mW] Set 105 simulating skin thickness of 2 mm Set105 simulating skin thickness of 2 mm 105a 3.5 10 105a 3.5 11 105b 3.613 105b 3.6 14 105c 3.7 17 105c 3.7 19 Set 106 simulating skin thicknessof 2.25 mm Set 106 simulating skin thickness of 2.25 mm 106a 3.5 9 106a3.5 10 106b 3.6 12 106b 3.6 13 106c 3.7 16 106c 3.7 18

Processor 110 may form lookup tables, such as for example, table 1 andsave the illumination intensities associated with the specific skincharacteristics and the specific concentration in a memory (e.g., memory250) of the device (e.g., device 10) for measuring materialsconcentration, in operation 440.

In some embodiments, some of the sets from the at least two sets ofcalibrating elements may include simulating a human skin with a firstamount of color pigments and some of the sets from the at least two setsof calibrating elements includes simulating a human skin with a secondamount of color pigments. In some embodiments, the received illuminationintensities may include illumination intensities received fromcalibrating elements simulating a human skin with the first and secondamount of color pigments. Accordingly, the lookup tables may furtherinclude illumination intensities associated with specific skin thicknesshaving specific color (e.g., amount of pigment in the skin).

Accordingly, when device 10 is attached to a human's skin (e.g., humanhand) with known skin thickness a reading from sensor 210 followingillumination at a known wavelength may be accurately associated to aconcentration of one or more materials (e.g., albumin and glucose) inthe blood using the lookup tables stored in memory 250.

While certain features of the invention have been illustrated anddescribed herein, many modifications, substitutions, changes, andequivalents will now occur to those of ordinary skill in the art. It is,therefore, to be understood that the appended claims are intended tocover all such modifications and changes as fall within the true spiritof the invention.

The invention claimed is:
 1. A system for calibrating a device formeasuring materials concentration in blood, comprising: at least twosets of calibrating elements, each set comprising a plurality ofcalibrating elements, wherein each of the calibrating elementscomprises: a first layer simulating a specific human skincharacteristic; and a second layer comprising a specific concentrationof one or more materials in the blood; and a third layer simulatingillumination reflection from a blood vessel in a skin tissue, whereinthe specific skin characteristics are selected from skin thickness, skincolor, skin hair density, skin tone, an amount of pigment in the skin,skin optical properties and skin hair color; wherein in all calibratingelements in a set the first layer is the same first layer simulating thesame human skin characteristics and each set of calibrating elementssimulate different skin characteristics, wherein each calibratingelement in a set of calibrating elements comprises a different secondlayer comprising a different concentration of the one or more materials;and wherein the third layer isolates the calibrating element from noiseand reflections not related to the measured one or more materials in thesecond layer; and a controller configured to: receive illuminationintensities from the device for measuring materials concentration whenthe device is attached to each calibrating element of the system;associate the received illumination intensities with the specific skincharacteristics and the specific concentration of the calibratingelement to which the device is attached; and save the illuminationintensities associated with the specific skin characteristics and thespecific concentration in lookup tables in memory of the device formeasuring materials concentration.
 2. The system of claim 1, wherein thereceived illumination intensities include illumination intensities atvarious wavelengths and wherein the saved lookup tables include lookuptables for illumination intensities of a specific wavelength associatedwith the specific skin characteristics, the one or more materials andthe specific concentration.
 3. A system for calibrating a device formeasuring materials concentration in blood, comprising: a first set ofcalibrating elements; a second set of calibrating elements, wherein eachof the calibrating elements in the first set and in the second setcomprises: a first layer simulating a specific human skincharacteristic; a second layer comprising a specific concentration ofone or more materials in the blood; and a third layer simulatingillumination reflection from a blood vessel in a skin tissue, whereinthe specific skin characteristics are selected from skin thickness, skincolor, skin hair density, skin tone, an amount of pigment in the skin,skin optical properties and skin hair color; wherein in the first set ofcalibrating elements the first layer simulates a first human skincharacteristic and in the second set of calibrating elements the firstlayer simulates a second human skin characteristic, different from thefirst human skin characteristic, wherein each calibrating element in thefirst set comprises a different second layer comprising a differentconcentration of the one or more materials, and wherein each calibratingelement in the second set comprises a different second layer comprisinga different concentration of the one or more materials; the third layerisolates the calibrating element from noise and reflections not relatedto the measured one or more materials in the second layer; and acontroller configured to: receive illumination intensities from thedevice for measuring materials concentration when the device is attachedto each calibrating element of the system; associate the receivedillumination intensities with the specific skin characteristic and thespecific concentration of the measured one or more materials in thesecond layer of the calibrating element to which the device is attached;and save the illumination intensities associated with the specific skinthicknesses and the specific concentrations in a memory of the devicefor measuring materials concentration.
 4. The system of claim 3, whereinthe received illumination intensities include illumination intensitiesat various wavelengths and wherein the saved lookup tables includelookup tables for illumination intensities of a specific wavelengthassociated with the specific skin characteristics, the one or morematerials and the specific concentration.
 5. A method of calibrating adevice for measuring materials concentration in blood, the methodcomprising: attaching the device for measuring materials concentrationto each calibrating element included in one of two or more sets ofcalibrating elements, wherein each of the calibrating elementscomprises: a first layer simulating a specific human skincharacteristic; a second layer comprising a specific concentration ofone or more materials; and a third layer simulating illuminationreflection from a blood vessel in a skin tissue, wherein the specificskin characteristics are selected from skin thickness, skin color, skinhair density, skin tone, an amount of pigment in the skin, skin opticalproperties and skin hair color; wherein in all calibrating elements in aset the first layer is the same first layer simulating the same humanskin characteristic and each set of calibrating elements simulatedifferent skin characteristic, wherein each calibrating element in a setof calibrating elements comprises a different second layer comprising adifferent concentration of the one or more materials; and wherein thethird layer isolates the calibrating element from noise and reflectionsnot related to the measured one or more materials in the second layer;receiving, by a controller of a calibrating system, illuminationintensities from the device for measuring materials concentration whenthe device is attached to each calibrating element; associating, by thecontroller, the received illumination intensities with the specific skincharacteristic and the specific concentration of the one or morematerials in the second layer of the calibrating element to which thedevice is attached; and recording, by the controller, the illuminationintensities associated with the specific skin characteristic and thespecific concentrations in a memory of the device for measuringmaterials concentration.
 6. The method of claim 5, wherein receivingillumination intensities includes receiving illumination intensities atvarious wavelengths and wherein recording the illumination intensitiesincludes creating lookup tables for illumination intensities of aspecific wavelength associated with the specific skin characteristic andthe specific concentration.